Hester et al., Tetrahedron Letters, No. 20, pp. 1609-1612 (1971) disclose several 1,4-benzodiazepines with heterocyclic groups fused on the "a" and "d" benzodiazepine faces. The 6-phenyl-4H-tetrazolo-[1,4-a][1,4]benzodiazepines are said to be sedatives and tranquilizers (U.S. Pat. No. 3,717,653). Peet et al., J. Het. Chem. 14 561 (1977) disclose 5H-tetrazolo[1,5-d][1,4]benzodiazepin-6(7H)-one derivatives and Madronero et al., J. Het. Chem., 15 1127 (1978) discloses tetrazolo-[1,5-d][1,4]benzodiazepine derivatives (the designation of Compound VIII on page 1127 as a tetrazolo [1,5-a]-derivative is in error because the face of attachment is "d").